c-dilks / hipo-cppyy

Example reading HIPO with `cppyy` bindings to the C++ HIPO API

hipo-cppyy

Example reading HIPO with cppyy Python bindings to the C++ HIPO API

Setup: Install the Dependencies

Before doing anything, clone this repository

git clone https://github.com/c-dilks/hipo-cppyy.git

Then cd into it, since most of the following instructions assume you are working from within it

cd hipo-cppyy

(you may prefer not to work in the hipo-cppyy directory, so modify the following commands as needed).

🔶 hipo: C++ HIPO API

https://github.com/gavalian/hipo

Download the latest release of HIPO (set by the --branch option), and install it to a local directory ./install; click here for the list of HIPO releases, since the version used in this example will be out of date someday:

git clone https://github.com/gavalian/hipo.git --branch 4.0.1 --recurse-submodules
cmake -S hipo -B hipo/build -DCMAKE_INSTALL_PREFIX=$(pwd)/install -DCMAKE_C_COMPILER=$(which gcc)   # -DCMAKE_C_COMPILER is needed, if on ifarm
cmake --build hipo/build
cmake --install hipo/build

🔶 Python Virtual Environment

Before installing Python packages, it's good practice to create a Python virtual environment, otherwise these next steps will install the Python packages at the system level.

Doing this is optional, but if you work with a lot of Python code, it may be a good idea.

Various guides are available online, for example: https://docs.python.org/3/library/venv.html

Following this guide, we can create a local virtual environment in ./venv:

python3 -m venv ./venv

Then activate it:

source venv/bin/activate

🔶 Python Packages

Whether or not you are using a Python virtual environment or Python from the system level (run which python3 to check), install the required Python packages:

python3 -m pip install pkgconfig cppyy matplotlib PyQt5

Package	Description
pkgconfig	Python wrapper for pkg-config dependency resolution
cppyy	Automated C++ / Python bindings
matplotlib	Data visualization
PyQt5	Supports matplotlib usage

Run the Example

Set your Environment

If you have installed hipo to ./install, you may just run:

source environ.sh

If not, check environ.sh to see what environment variables are set, and set them yourself according to your installation.

Sourcing environ.sh will also activate your Python virtual environment, if it's in ./venv.

Try the Example

Running with no arguments will print the usage guide:

python3 ./example.py

It will draw the momentum distribution of pions, and the plot will be saved as plot.png.

See the script example.py for more details.